JP6106789B1 - Oxide superconducting wire, manufacturing method thereof, and superconducting coil - Google Patents

Abstract

Disclosed are an oxide superconducting wire that does not deteriorate even when an external force is applied, a method for manufacturing the same, and a superconducting coil. An oxide superconducting laminate, a metal stabilizing layer that covers the oxide superconducting laminate, and a bonding metal layer that joins the metal stabilizing layer to the oxide superconducting laminate are provided. Oxide superconducting wire A. The oxide superconducting laminate 1 has a main part 11 having a tape-like substrate 3 and a superconducting part 12 having an oxide superconducting layer 5. Superconducting portion 12 is narrower than main portion 11 and is stacked on one surface of main portion 11. The bonding metal layer 7 is interposed at least between at least one side surface 12 d of the superconducting portion 12 and the metal stabilization layer 8. [Selection] Figure 1

Description

  The present invention relates to an oxide superconducting wire, a manufacturing method thereof, and a superconducting coil.

Conventionally, an oxide superconducting wire having a laminate having a base material and an oxide superconducting layer and a covering portion covering the laminate has been proposed (see, for example, Patent Documents 1 and 2).
The covering portion has a metal stabilizing layer made of a plating layer, a metal foil, or the like. The metal stabilizing layer protects the laminated body to ensure the mechanical strength of the oxide superconducting wire, and prevents intrusion of moisture and the like, thereby preventing deterioration of superconducting characteristics.

JP 2012-043734 A JP-A-2015-146318

A superconducting device such as a superconducting magnet or a superconducting motive may use a plurality of laminated pancake superconducting coils. The superconducting coil is made of, for example, an oxide superconducting wire. When the superconducting coil is energized, electromagnetic force acts in the thickness direction of the superconducting coil. When a strong compressive force acts on the side of the oxide superconducting wire due to this electromagnetic force, the side of the metal stabilization layer is damaged, causing delamination, moisture intrusion, etc. starting from the damaged part, and the characteristics of the superconducting coil There is a possibility of deterioration.
It is an object of the present invention to provide an oxide superconducting wire that does not deteriorate characteristics even when an external force is applied, a method for manufacturing the same, and a superconducting coil.

One aspect of the present invention includes an oxide superconducting laminate, a metal stabilizing layer that covers the oxide superconducting laminate, and a bonding metal layer that joins the metal stabilizing layer to the oxide superconducting laminate, The oxide superconducting laminate has a main part having a tape-shaped substrate and a superconducting part having an oxide superconducting layer, and the superconducting part is narrower than the main part, and is one of the main parts. The oxide superconducting wire is laminated on a surface, and the joining metal layer is interposed at least between at least one side surface of the superconducting portion and the metal stabilizing layer.
According to this configuration, since the oxide superconducting layer is formed to be narrower than the main part, even if a force in the width direction is applied to the side part of the oxide superconducting wire from the outside, the influence is exerted on the oxide superconducting layer. Hateful. For example, even if the side portion of the covering portion is damaged by an external force, the oxide superconducting layer does not peel off. Further, even if the side portion of the covering portion is damaged, the damage does not reach the oxide superconducting layer. Therefore, even if moisture enters from the damaged portion, the water immersion does not reach the oxide superconducting layer.
When a plurality of superconducting coils using oxide superconducting wires are stacked, a force in the coil thickness direction (wire width direction) may be applied by energization. Since it is difficult to affect the layer, it is possible to avoid deterioration of the characteristics of the superconducting coil due to damage of the covering portion.
Further, the bonding metal layer can enhance the adhesion of the metal stabilizing layer to the oxide superconducting laminate, and the metal stabilizing layer can be firmly bonded to the oxide superconducting laminate. Therefore, it is possible to increase the mechanical strength of the side portion of the oxide superconducting wire, protect the end portion in the width direction of the superconducting portion (particularly the end portion in the width direction of the oxide superconducting layer), and prevent damage. Moreover, water resistance can be improved by improving the adhesiveness of the metal stabilization layer with respect to an oxide superconducting laminated body.

The total thickness of the bonding metal layer and the metal stabilizing layer on the side surface of the superconducting portion is the distance in the width direction between the end portion in the width direction of the main portion and the end portion in the width direction of the oxide superconducting layer. Larger is preferred.
This increases the mechanical strength of the side portion of the oxide superconducting wire, protects the end portion in the width direction of the superconducting portion (particularly the end portion in the width direction of the oxide superconducting layer), and prevents damage.

At least one of the end portions in the width direction of the oxide superconducting layer is preferably located 300 μm or more closer to the center in the width direction than the end portion in the width direction of the main portion in plan view.
According to this configuration, even if the side portion of the covering portion receives an external force, the influence hardly reaches the oxide superconducting layer.

The metal stabilization layer is, for example, a plating layer.
According to this configuration, since the superconducting portion can be easily formed, the oxide superconducting wire can be easily manufactured.

The metal stabilization layer is made of, for example, a metal tape.
According to this configuration, since the superconducting portion can be easily formed, the oxide superconducting wire can be easily manufactured.

One aspect of the present invention provides a superconducting coil including the oxide superconducting wire.
According to this configuration, even if a force in the width direction of the oxide superconducting wire is applied from the outside, it is difficult to affect the oxide superconducting layer, so that deterioration of the characteristics of the superconducting coil can be avoided.

One embodiment of the present invention includes an oxide superconducting laminate including a main part having a tape-like base material and a superconducting part having an oxide superconducting layer, and the superconducting part is laminated on one surface of the main part. Forming the superconducting part so that the width is narrower than the main part by removing a part of the superconducting part in the width direction, and stabilizing the metal covering the oxide superconducting laminate. Forming a bonding layer, and a bonding metal layer for bonding the metal stabilization layer to the oxide superconducting laminate, and in the step of forming the metal stabilization layer and the bonding metal layer, the bonding The metal layer provides at least a method for producing an oxide superconducting wire interposed between at least one side surface of the superconducting portion and the metal stabilizing layer.
According to this method, since the superconducting portion can be easily formed, an oxide superconducting wire can be easily manufactured.

In the step of forming the superconducting part so as to be narrower than the main part, a method of removing a part of the superconducting part in the width direction by laser processing can be employed.
According to this method, since the superconducting portion can be easily formed, an oxide superconducting wire can be easily manufactured.

In the step of forming the superconducting part so as to be narrower than the main part, a method of removing a part of the superconducting part in the width direction by etching can be employed.
According to this method, since the superconducting portion can be easily formed, an oxide superconducting wire can be easily manufactured.

  According to one aspect of the present invention, even if an external force in the width direction of the oxide superconducting wire is applied, the influence hardly affects the oxide superconducting layer. Therefore, it is possible to avoid deterioration of the characteristics of the superconducting coil using the oxide superconducting wire.

It is sectional drawing which shows typically the oxide superconducting wire of 1st Embodiment. It is a perspective view which shows an example of the oxide superconducting laminated body of the oxide superconducting wire shown in FIG. It is process drawing which shows typically an example of the manufacturing process of the oxide superconducting wire shown in FIG. It is process drawing following a previous figure. It is process drawing following a previous figure. It is process drawing following a previous figure. It is sectional drawing which shows typically the oxide superconducting wire of 2nd Embodiment. It is the schematic which shows typically an example of the manufacturing process of the oxide superconducting wire shown to a previous figure. It is sectional drawing which shows typically the oxide superconducting wire of 3rd Embodiment. It is the schematic which shows typically an example of the manufacturing process of the oxide superconducting wire shown to a previous figure. It is sectional drawing which shows the modification of the oxide superconducting laminated body of the oxide superconducting wire of 1st Embodiment. It is the schematic which shows the superconducting coil provided with the oxide superconducting wire of embodiment.

An embodiment of an oxide superconducting wire according to the present invention will be described with reference to the drawings. In the following description, an XYZ orthogonal coordinate system is adopted. The Y direction is the length direction of the wire. The X direction is a direction in the plane of the surface of the wire and orthogonal to the Y direction, and is the width direction of the wire. The Z direction is a direction orthogonal to the X direction and the Y direction, and is the thickness direction of the wire.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent. Hereinafter, the oxide superconducting wire may be simply referred to as “wire”. The present invention is not limited to the following embodiments.

[Oxide superconducting wire (first embodiment)]
FIG. 1 is a cross-sectional view schematically showing an oxide superconducting wire A which is an oxide superconducting wire according to the first embodiment. FIG. 2 is a perspective view schematically showing an example of the oxide superconducting laminate 1 of the oxide superconducting wire A. FIG. Note that the plan view refers to viewing in parallel with the thickness direction of the substrate 3. In FIG. 1, the oxide superconducting layer 5 is located above the base material 3. C1 is the center in the width direction of the oxide superconducting laminate 1.

As shown in FIGS. 1 and 2, the oxide superconducting wire A includes an oxide superconducting laminate 1 and a covering portion 2.
The oxide superconducting laminate 1 has a main part 11 and a superconducting part 12 laminated on one surface 11a (upper surface in FIG. 1) of the main part 11.
The main part 11 includes, for example, a base material 3 and an intermediate layer 4 laminated on one surface 3a (upper surface in FIG. 1) of the base material 3. The surface 11 a of the main part 11 is the surface 4 a of the intermediate layer 4. The base material 3 and the intermediate layer 4 have the same width, and the planar view position (position in the width direction) matches.

  The substrate 3 is preferably in the form of a tape, and is preferably formed of a heat resistant metal. Flexibility can be given to the oxide superconducting wire A by making the base material 3 into a tape shape. As the heat-resistant metal constituting the substrate 3, a nickel alloy is preferable. In particular, if it is a commercial product, Hastelloy (trade name, manufactured by Haynes, USA) is suitable. The thickness of the base material 3 is 10-500 micrometers, for example.

As the intermediate layer 4, a structure formed by an underlayer, an alignment layer, and a cap layer can be applied as an example.
When the underlayer is provided, a multi-layer structure formed by the diffusion preventing layer and the bed layer, or a structure formed by any one of these layers can be adopted as the underlayer. When a diffusion prevention layer is provided as an underlayer, the diffusion prevention layer is composed of a single layer structure made of silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ ), GZO (Gd ₂ Zr ₂ O ₇ ), or the like. Or the layer of a multilayer structure is desirable and the thickness is 10-400 nm, for example.

When a bed layer is provided as an underlayer, the bed layer has high heat resistance, reduces interfacial reactivity, and is used for obtaining the orientation of a film disposed thereon. Bed layer is made of, for _{example, Y 2 O 3, Er 2 O} 3, CeO 2, Dy 2 O 3, Er 2 O 3, Eu 2 O 3, Ho 2 O 3, La 2 O 3 and the like. The bed layer can adopt a single layer structure or a multilayer structure formed of these materials. The thickness of the bed layer is, for example, 10 to 100 nm.

The alignment layer functions as a buffer layer for controlling the crystal orientation of the oxide superconducting layer 5 formed on the alignment layer. The alignment layer is preferably formed of a metal oxide having good lattice matching with the oxide superconducting layer. Specific examples of preferable materials for the alignment layer include Gd ₂ Zr ₂ O ₇ , MgO, ZrO ₂ —Y ₂ O ₃ (YSZ), SrTiO ₃ , CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , Gd _2. Examples thereof include metal oxides such as O ₃ , ZrO ₂ , Ho ₂ O ₃ , and Nd ₂ O ₃ . The alignment layer may have a single layer structure or a multilayer structure.

The cap layer is formed on the surface of the above-described alignment layer and is made of a material that allows crystal grains to self-orient in the in-plane direction. Specifically, CeO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , Gd _{2 O 3, ZrO 2, YSZ,} Ho 2 O 3, Nd 2 O 3, consist of LaMnO ₃ like. The thickness of the cap layer can be in the range of 50 to 5000 nm, for example.

  Superconducting portion 12 has oxide superconducting layer 5 formed on surface 4a of intermediate layer 4, and protective layer 6 (first protective layer) formed on surface 5a of oxide superconducting layer 5. The oxide superconducting layer 5 and the protective layer 6 have the same width, and the plan view position (position in the width direction) coincides.

The oxide superconducting layer 5 can be widely applied with a composition of a generally known oxide superconductor, and REBa ₂ Cu ₃ O _y (RE is a rare earth element such as Y, La, Nd, Sm, Er, and Gd). In particular, Y123 (YBa ₂ Cu ₃ O _y ) or Gd123 (GdBa ₂ Cu ₃ O _y ) can be exemplified. Further, other oxide superconductors, for _example, a _{Bi 2 Sr 2 Ca n-1} Cu n O 4 + 2n + δ materials which are formed in high other oxide superconductors having a critical temperature represented by the composition or the like formed by using Of course, it may be. The oxide superconducting layer 5 has a thickness of about 0.5 to 5 μm and preferably a uniform thickness.

The protective layer 6 functions as a bypass that commutates the current of the oxide superconducting layer 5 when the oxide superconducting layer 5 transitions from the superconducting state to the normal conducting state. The protective layer 6 is made of, for example, silver (Ag), gold (Au), an alloy of gold and silver, other silver alloys, or gold alloys.
The thickness of the protective layer 6 is about 1 to 30 μm. The protective layer 6 is formed so as to cover the surface 5 a of the oxide superconducting layer 5.

The width (the dimension in the X direction) of the superconducting portion 12 is narrower than the width of the main portion 11. The end portions 12b and 12b (side edge portions) in the width direction of the superconducting portion 12 are positioned closer to the center in the width direction than the end portions 11b and 11b (side edge portions) in the width direction of the main portion 11 in plan view, for example. To do. Therefore, the planar view positions of the end portions 5b and 5b (side edge portions) in the width direction of the oxide superconducting layer 5 are closer to the center C1 in the width direction than the end portions 11b and 11b in the width direction of the main portion 11.
The end portions 5 b and 5 b in the width direction of the oxide superconducting layer 5 are preferably closer to the center than the end portions 11 b and 11 b in the width direction of the main portion 11 over the entire length of the oxide superconducting layer 5.
Of the surface 11a of the main portion 11 (the surface 4a of the intermediate layer 4), regions where the superconducting portion 12 is not formed are referred to as side surface regions 11c and 11c.

The distance L1 in the width direction between the end portion 11b in the width direction of the main portion 11 and the end portion 5b in the width direction of the oxide superconducting layer 5 is preferably 300 μm or more (preferably 500 μm or more). When the distance L1 is 300 μm or more, even if the side portion of the covering portion 2 receives an external force, the influence hardly reaches the oxide superconducting layer 5. For example, even if a damage (crack) of 10 to 100 μm occurs in the width direction on the side portion of the covering portion 2, the damage does not reach the oxide superconducting layer 5.
The distance L1 can be set to 1000 μm or less, for example. When the distance L1 is 1000 μm or less, a sufficient width can be secured in the oxide superconducting layer 5 and the critical current characteristics of the oxide superconducting wire A can be enhanced.
The width direction distance L1 between the end portion 11b in the width direction of the main portion 11 and the end portion 5b in the width direction of the oxide superconducting layer 5 corresponds to, for example, the width of the side surface region 11c.

  The width W2 of the oxide superconducting layer 5 is preferably at least half of the width W1 of the substrate 3. Thereby, a sufficient width can be secured for the oxide superconducting layer 5 and the critical current characteristics of the oxide superconducting wire A can be enhanced.

As shown in FIG. 11, when the end surface of the end portion 5b in the width direction of the oxide superconducting layer 5 is inclined with respect to the YZ plane, the distance L1 is equal to the outermost edge 5b1 of the end portion 5b in the width direction ( This is the distance in the width direction between the outermost portion in the width direction in plan view) and the end portion 11b in the width direction of the main portion 11, and the minimum distance between the end portion 5b in the width direction and the end portion 11b in the width direction. . The width W2 of the oxide superconducting layer 5 in this case is the distance between the outermost edges 5b1 and 5b1.
In addition, in the oxide superconducting wire A shown in FIG. 1, both ends 5b and 5b in the width direction of the oxide superconducting layer 5 are closer to the center C1 than the ends 11b and 11b in the width direction of the main portion 11 in plan view. However, only one of the end portions 5b and 5b in the width direction of the oxide superconducting layer 5 may be closer to the center C1 than the end portion 11b in the width direction of the main portion 11. For example, in plan view, only one of the end portions 5b and 5b in the width direction of the oxide superconducting layer 5 is closer to the center C1 than the end portion 11b in the width direction of the main portion 11 and the other end portion 5b in the other width direction. The planar view position may coincide with the planar view position (position in the width direction) of the end portion 11b of the main portion 11 in the width direction.

As shown in FIG. 1, the covering portion 2 includes a bonding metal layer 7 (second protective layer, covering metal layer) and a metal stabilization layer 8 formed on the outer surface of the bonding metal layer 7.
The bonding metal layer 7 extends in the length direction of the oxide superconducting laminate 1 and is formed so as to cover the oxide superconducting laminate 1. The bonding metal layer 7 enhances the adhesion of the metal stabilizing layer 8 to the oxide superconducting laminate 1 and firmly bonds the metal stabilizing layer 8 to the oxide superconducting laminate 1. Therefore, the mechanical strength of the covering portion 2 can be increased and the covering portion 2 can be made difficult to break.
The material constituting the bonding metal layer 7 is not particularly limited as long as it has good conductivity, but copper, copper alloy (Cu-Zn alloy, Cu-Ni alloy, etc.), Au, Au alloy, or the like may be used. preferable. Of these, copper is preferable because it has high conductivity and is inexpensive.

The metal stabilizing layer 8 extends in the length direction of the oxide superconducting laminate 1 and is formed so as to cover the oxide superconducting laminate 1 via the bonding metal layer 7. The metal stabilizing layer 8 functions as a bypass for commutating current together with the protective layer 6 when the oxide superconducting layer 5 is transitioned from the superconducting state to the normal conducting state.
The material constituting the metal stabilizing layer 8 is not particularly limited as long as it has good conductivity. However, copper, copper alloys (Cu-Zn alloy, Cu-Ni alloy, etc.), Al, Al alloys (Al-Cu) It is preferable to use a relatively inexpensive material such as an alloy. Of these, copper is preferable because it has high conductivity and is inexpensive. Although the thickness of the metal stabilization layer 8 is not specifically limited, For example, it is preferable to set it as 15-300 micrometers.
The metal stabilization layer 8 is preferably a plating layer formed by a plating method.

The covering portion 2 includes the other surface 3b of the base 3 of the oxide superconducting laminate 1, the side surfaces 11d and 11d of the main portion 11, the side surface regions 11c and 11c, and the side surfaces 12b and 12b of the superconducting portion 12. The superconducting portion 12 is formed so as to cover the surface 12a (the surface 6a of the protective layer 6).
Specifically, the bonding metal layer 7 includes the other surface 3b of the substrate 3, the side surfaces 11d and 11d of the main portion 11, the side surface regions 11c and 11c, the side surfaces 12b and 12b of the superconducting portion 12, and the superconducting portion. 12 surface 12a (surface 6a of protective layer 6) is formed so as to cover without a gap. Therefore, the bonding metal layer 7 is formed on the outer surface of the oxide superconducting laminate 1 (the other surface 3b of the base material 3, the side surfaces 11d and 11d of the main portion 11, the side surface regions 11c and 11c, and the side surface 12b of the superconducting portion 12). 12b, the surface 12a of the superconducting portion 12 (the surface 6a of the protective layer 6)) and the metal stabilizing layer 8 are interposed.

  Since the metal stabilization layer 8 is formed so as to cover the entire outer surface of the bonding metal layer 7, the other surface 3 b of the substrate 3 and the side surfaces 11 d and 11 d of the main part 11 are interposed via the bonding metal layer 7. And side surface regions 11c and 11c, side surfaces 12b and 12b of superconducting portion 12, and surface 12a of superconducting portion 12 (surface 6a of protective layer 6).

Thickness (width direction (X direction) dimension) of covering portion 2 on side surfaces 12d and 12d of superconducting portion 12 T1 (total thickness of bonding metal layer 7 and metal stabilizing layer 8) (for example, maximum thickness) Is preferably larger than the distance L1 in the width direction between the end portion 11b in the width direction of the main portion 11 and the end portion 5b in the width direction of the oxide superconducting layer 5.
Thereby, the mechanical strength of the side portion of the oxide superconducting wire A is increased, and the end portions 12b and 12b in the width direction of the superconducting portion 12 (particularly the end portions 5b and 5b in the width direction of the oxide superconducting layer 5) are protected. Can prevent damage.

  A thickness T2 of the covering portion 2 along the side surface 11d of the main portion 11 is, for example, 20 μm or more. By setting the thickness T2 of the covering portion 2 to 20 μm or more, the covering portion 2 is hardly damaged. The thickness T2 can be 100 μm or less. By setting the thickness T2 to 100 μm or less, the line width of the oxide superconducting wire A can be suppressed.

[Production Method of Oxide Superconducting Wire (First Embodiment)]
The manufacturing method of the first embodiment will be described by taking as an example the case of manufacturing the oxide superconducting wire A shown in FIG.

(Step 1: Preparation of oxide superconducting laminate)
The oxide superconducting laminate 1A shown in FIG. 3 is produced as follows.
First, the intermediate layer 4 is formed on one surface 3 a of the substrate 3. The intermediate layer 4 includes, for example, a base layer, an alignment layer, and a cap layer.
When a diffusion prevention layer is provided as the underlayer, the diffusion prevention layer can be formed by a film formation method such as sputtering. When a bed layer is provided as the base layer, the bed layer can be formed by a film formation method such as a sputtering method. The alignment layer can be formed by a physical vapor deposition method such as an ion beam assisted vapor deposition method (IBAD method). The cap layer can be formed by a PLD method (pulse laser deposition method), a sputtering method, or the like. When the CeO ₂ layer is formed by the PLD method, it can be formed in an oxygen gas atmosphere at a substrate temperature of about 500 to 1000 ° C. and about 0.6 to 100 Pa.
As a result, a main portion 11 composed of the base material 3 and the intermediate layer 4 is obtained.

  An oxide superconducting layer 5A is formed on the surface 4a of the intermediate layer 4. The oxide superconducting layer 5A is formed by sputtering, vacuum vapor deposition, laser vapor deposition, electron beam vapor deposition, pulsed laser deposition (PLD), chemical vapor deposition (CVD), or organic metal coating pyrolysis (MOD). Etc.). The oxide superconducting layer 5 </ b> A has the same width as the intermediate layer 4, and the position in plan view coincides with the intermediate layer 4.

  A protective layer 6A is formed on the surface 5Aa of the oxide superconducting layer 5A. The protective layer 6A can be formed by a sputtering method using a DC sputtering device, an RF sputtering device, or the like. The protective layer 6A has the same width as the oxide superconducting layer 5A, and the position in plan view coincides with the oxide superconducting layer 5A. By forming the protective layer 6A, the superconducting portion 12A composed of the oxide superconducting layer 5A and the protective layer 6A is formed.

  As a result, an oxide superconducting laminate 1A having a main part 11 and a superconducting part 12A is obtained. Of the superconducting portion 12A, portions including the end portions 5Ab, 5Ab in the width direction of the oxide superconducting layer 5A and the end portions 6Ab, 6Ab in the width direction of the protective layer 6A are referred to as side portions 13, 13. The side portions 13 and 13 are portions including end portions 12Ab and 12Ab in the width direction of the superconducting portion 12A, and are portions having a constant width along the length direction of the oxide superconducting laminate 1A.

(Step 2: Remove side portion 13 of superconducting portion 12A)
As shown in FIG. 4, a mask 17 is formed in a region (central region 16) excluding the side portions 13 and 13 on the surface of the protective layer 6A.
As shown in FIG. 5, the side portions 13 and 13 are removed by chemical processing such as etching. For the etching, for example, a wet etching method using an acidic or alkaline etching solution can be employed. As the etching solution, for example, nitric acid, sulfuric acid, hydrochloric acid, hydrogen peroxide water, ammonia water, or the like can be used.
Next, the mask 17 is removed. Thereby, the oxide superconducting laminate 1 is obtained.

(Process 3: Joining metal layer 7 is formed)
As shown in FIG. 6, the bonding metal layer 7 is formed by a film forming method such as a sputtering method or a vacuum evaporation method.

(Step 4: Form metal stabilization layer 8)
A metal stabilizing layer 8 (see FIG. 1) is formed by plating. As a result, the covering portion 2 composed of the bonding metal layer 7 and the metal stabilization layer 8 is formed.
Through the above steps, the oxide superconducting wire A shown in FIG. 1 is obtained.

In the oxide superconducting wire A, the oxide superconducting layer 5 is formed so as to be narrower than the main portion 11, and the widthwise ends 5 b and 5 b are closer to the widthwise ends 11 b and 11 b of the main portion 11. Is located. Therefore, even if a force in the width direction is applied to the side portion of the oxide superconducting wire A from the outside, the influence hardly affects the oxide superconducting layer 5. For example, even if the side portion of the covering portion 2 is damaged by an external force, the oxide superconducting layer 5 does not peel off. Further, even if the side portion of the covering portion 2 is damaged, the damage does not reach the oxide superconducting layer 5, so that the water does not reach the oxide superconducting layer 5 even if moisture enters from the damaged portion.
When a plurality of superconducting coils using the oxide superconducting wire A are stacked, a force in the coil thickness direction (the width direction of the wire) may be applied by energization, but the oxide superconducting wire A is oxidized in the width direction. Since it is difficult to influence the physical superconducting layer 5, it is possible to avoid deterioration of the characteristics of the superconducting coil due to damage to the covering portion 2 or the like.
In the oxide superconducting wire A, the bonding metal layer 7 increases the adhesion of the metal stabilizing layer 8 to the oxide superconducting laminate 1, and the metal stabilizing layer 8 can be firmly bonded to the oxide superconducting laminate 1. it can. Therefore, the mechanical strength of the side portion of the oxide superconducting wire A is increased, and the end portions 12b and 12b in the width direction of the superconducting portion 12 (particularly the end portions 5b and 5b in the width direction of the oxide superconducting layer 5) are protected. Damage can be prevented. Moreover, water resistance can be improved by improving the adhesiveness of the metal stabilization layer 8 with respect to the oxide superconducting laminated body 1. FIG.

  According to the manufacturing method, since the superconducting portion 12 is formed by removing the side portions 13 and 13 by chemical processing such as etching, the superconducting portion 12 can be easily formed. Therefore, the oxide superconducting wire A can be easily manufactured.

[Oxide superconducting wire (second embodiment)]
FIG. 7 is a cross-sectional view schematically showing an oxide superconducting wire B which is an oxide superconducting wire according to the second embodiment. In addition, about the same structure as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
As shown in FIG. 7, the oxide superconducting wire B includes an oxide superconducting laminate 1 and a covering portion 22. The oxide superconducting wire B has the same configuration as the oxide superconducting wire A of the first embodiment except for the covering portion 22.

The covering portion 22 includes a first bonding metal layer 7, a second bonding metal layer 27, and a metal stabilization layer 28.
The first bonding metal layer 7 may have the same configuration as the bonding metal layer 7 in the oxide superconducting wire A according to the first embodiment.
As a material constituting the second bonding metal layer 27, for example, Sn-based, Sn-Pb-based, Sn-Ag-Cu-based, Sn-Bi-based, In-based, Sn-In-based solders can be used. The second bonding metal layer 27 is formed so as to cover the oxide superconducting laminate 1 with the first bonding metal layer 7 interposed therebetween. The second bonding metal layer 27 is filled so as to fill a space between the first bonding metal layer 7 and the metal stabilization layer 28.
The bonding metal layers 7 and 27 enhance the adhesion of the metal stabilizing layer 28 to the oxide superconducting laminate 1 and firmly bond the metal stabilizing layer 28 to the oxide superconducting laminate 1. Therefore, the mechanical strength of the covering portion 22 can be increased, and the covering portion 22 can be hardly damaged.

The metal stabilization layer 28 extends in the length direction of the oxide superconducting laminate 1 and is formed so as to cover the oxide superconducting laminate 1 via the bonding metal layers 7 and 27.
The metal stabilization layer 28 functions as a bypass for commutating current together with the protective layer 6 when the oxide superconducting layer 5 is transitioned from the superconducting state to the normal conducting state. The material constituting the metal stabilizing layer 28 is not particularly limited as long as it has good conductivity, but is not limited to copper, copper alloy (Cu-Zn alloy, Cu-Ni alloy, etc.), Al, Al alloy (Al-Cu). It is preferable to use a relatively inexpensive material such as an alloy. Of these, copper is preferable because it has high conductivity and is inexpensive.
Although the thickness of the metal stabilization layer 28 is not specifically limited, For example, it is preferable to set it as 15-300 micrometers.

The metal stabilization layer 28 has a base portion 28a, side portions 28b and 28b, and opposing portions 28c and 28c.
The base portion 28a covers the surface of the oxide superconducting laminate 1 on the oxide superconducting layer 5 side (upper surface in FIG. 7) via the bonding metal layers 7 and 27. The side portions 28 b and 28 b cover the side surface of the oxide superconducting laminate 1 with the bonding metal layers 7 and 27 interposed therebetween. The facing portions 28 c and 28 c cover part or all of the surface of the oxide superconducting laminate 1 on the base material 3 side through the bonding metal layers 7 and 27. The metal stabilization layer 28 is formed, for example, by bending a metal tape so that the cross section is substantially C-shaped.

  A buried layer 29 is formed at the center in the width direction of the oxide superconducting laminate 1 and between the facing portions 28c and 28c of the metal stabilizing layer 28 so as to fill a space between the facing portions 28c and 28c. Yes. The buried layer 29 is made of solder (Sn-based) or the like, and may be integrated with the bonding metal layer 27.

[Manufacturing Method of Oxide Superconducting Wire (Second Embodiment)]
The manufacturing method of 2nd Embodiment is demonstrated by taking the case where the oxide superconducting wire B shown in FIG. 7 is manufactured as an example.

(Step 1: Preparation of oxide superconducting laminate)
The oxide superconducting laminate 1A shown in FIG. 3 is obtained in the same manner as in step 1 of the manufacturing method of the first embodiment.

(Step 2: Remove side portion 13 of superconducting portion 12A)
In the same manner as in step 2 of the manufacturing method of the first embodiment, the side portions 13 and 13 of the superconducting portion 12A are removed to obtain the oxide superconducting laminate 1 (see FIGS. 4 and 5).

(Step 3: forming the first bonding metal layer 7)
The first bonding metal layer 7 is formed in the same manner as in step 3 of the manufacturing method of the first embodiment (see FIG. 6).

(Step 4: forming the second bonding metal layer 27 and the metal stabilization layer 28)
As shown in FIG. 8, a covering tape 2 </ b> A having a width wider than that of the oxide superconducting laminate 1 is prepared.
The covering tape 2A includes a metal tape 28A and a bonding metal layer 27A formed on the surface of the metal tape 28A. The bonding metal layer 27A is made of a metal such as solder (Sn-based) and can be formed by a plating method or the like.
The covering tape 2A is arranged along the length direction (Y direction) of the oxide superconducting laminate 1, and the oxide superconducting laminate 1 is wrapped and bent into a C-shaped cross section.

  The joining metal layer 27A is melted by heating. Molten metal (solder or the like) is filled in the gap between the oxide superconducting laminate 1 and the metal tape 28 </ b> A to form the second bonding metal layer 27. The buried layer 29 can be formed of the molten metal and a metal (solder or the like) added as necessary. The metal tape 28A becomes the metal stabilization layer 28. Thereby, the oxide superconducting wire B shown in FIG. 7 is obtained.

In the oxide superconducting wire B, as in the oxide superconducting wire A of the first embodiment, the widthwise ends 5b, 5b of the oxide superconducting layer 5 are wider than the widthwise ends 11b, 11b of the main portion 11. Since it is located near the center of the direction, even if it receives a force in the width direction of the wire from the outside, the influence hardly affects the oxide superconducting layer 5. Therefore, it is possible to avoid deterioration of the characteristics of the superconducting coil using the oxide superconducting wire A.
Similar to the oxide superconducting wire A of the first embodiment, the oxide superconducting wire B enhances the adhesion of the metal stabilizing layer 28 to the oxide superconducting laminate 1 by the first bonding metal layer 7 and stabilizes the metal. The layer 28 can be firmly bonded to the oxide superconducting laminate 1. Therefore, the mechanical strength of the side portion of the oxide superconducting wire B is increased, and the end portions 12b and 12b in the width direction of the superconducting portion 12 (particularly the end portions 5b and 5b in the width direction of the oxide superconducting layer 5) are protected. Damage can be prevented. Moreover, water resistance can be improved by improving the adhesiveness of the metal stabilization layer 28 with respect to the oxide superconducting laminated body 1. FIG.

[Oxide superconducting wire (third embodiment)]
FIG. 9 is a cross-sectional view schematically showing an oxide superconducting wire C which is an oxide superconducting wire according to the third embodiment. In addition, about the same structure as 1st Embodiment or 2nd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
As shown in FIG. 9, the oxide superconducting wire C includes an oxide superconducting laminate 31 and a covering portion 32.
The oxide superconducting laminate 31 has a main part 41 and a superconducting part 42 laminated on one surface 41a (upper surface in FIG. 9) of the main part 41.

The main portion 41 is made of the base material 3. A surface 41 a of the main portion 41 is the surface 3 a of the base material 3.
The superconducting portion 42 includes an intermediate layer 34 formed on the surface 3 a of the base material 3, an oxide superconducting layer 5 formed on the surface 34 a of the intermediate layer 34, and a protection formed on the surface 5 a of the oxide superconducting layer 5. Layer 6. The intermediate layer 34, the oxide superconducting layer 5, and the protective layer 6 have the same width, and coincide with each other in plan view.
The intermediate layer 34 can have the same configuration as the intermediate layer 4 in the oxide superconducting wire A of the first embodiment except for the width.

The width of the superconducting portion 42 (dimension in the X direction) is narrower than that of the main portion 41. The end portions 42b and 42b in the width direction of the superconducting portion 42 are located closer to the center in the width direction than the end portions 41b and 41b in the width direction of the main portion 41 in plan view. Therefore, the planar view positions of the end portions 5b and 5b in the width direction of the oxide superconducting layer 5 are closer to the center C1 in the width direction than the end portions 41b and 41b in the width direction of the main portion 41.
Of the surface 41a of the main portion 41 (the surface 3a of the base material 3), the region where the superconducting portion 42 is not formed is referred to as side surface regions 41c and 41c.

The covering portion 32 includes a bonding metal layer 37 and a metal stabilization layer 8 formed on the outer surface of the bonding metal layer 37.
The bonding metal layer 37 may have the same configuration as the bonding metal layer 7 in the oxide superconducting wire A of the first embodiment.
The covering portion 32 includes the other surface 3b of the base material 3, side surfaces 41d and 41d of the main portion 41, side surface regions 41c and 41c, side surfaces 42b and 42b of the superconducting portion 42, and a surface 42a of the superconducting portion 42. (Surface 6a of protective layer 6).

[Method for Producing Oxide Superconducting Wire (Third Embodiment)]
The manufacturing method of 3rd Embodiment is demonstrated by making the case where the oxide superconducting wire C shown in FIG. 9 is manufactured as an example.

(Step 1: Preparation of oxide superconducting laminate)
The oxide superconducting laminate 1A shown in FIG. 3 is obtained in the same manner as in step 1 of the manufacturing method (first example) of the first embodiment. In this step, the intermediate layer 4, the oxide superconducting layer 5A, and the protective layer 6A of the oxide superconducting laminate 1A are referred to as a superconducting portion 42A.

(Step 2: Remove side portion 43 of superconducting portion 42A)
As shown in FIG. 10, the laser beam 15 is irradiated to the side portions 43 and 43 including the end portions 42Ab and 42Ab in the width direction of the superconducting portion 42A by using the laser processing machine (laser irradiation device) 14, and the side portion 43 , 43 are removed. The side portions 43, 43 include end portions 5Ab, 5Ab in the width direction of the oxide superconducting layer 5A, end portions 6Ab, 6Ab in the width direction of the protective layer 6A, and end portions 4b, 4b in the width direction of the intermediate layer 4. It is a part of constant width including
Thereby, the oxide superconducting laminate 31 is obtained.

(Steps 3 and 4: forming the bonding metal layer 37 and the metal stabilization layer 8)
The bonding metal layer 37 and the metal stabilization layer 8 are formed in the same manner as in Steps 3 and 4 of the manufacturing method of the first embodiment.
Through the above steps, an oxide superconducting wire C shown in FIG. 9 is obtained.

In the oxide superconducting wire C, as in the oxide superconducting wire A of the first embodiment, the end portions 5b and 5b in the width direction of the oxide superconducting layer 5 are more central than the end portions 41b and 41b in the width direction of the main portion 41. Since they are located closer to each other, even if a force in the width direction of the wire is applied from the outside, the influence hardly affects the oxide superconducting layer 5. Therefore, it is possible to avoid deterioration of the characteristics of the superconducting coil using the oxide superconducting wire C.
Similar to the oxide superconducting wire A of the first embodiment, the oxide superconducting wire C enhances the adhesion of the metal stabilizing layer 8 to the oxide superconducting laminate 1 by the bonding metal layer 37, and the metal stabilizing layer 8. Can be firmly bonded to the oxide superconducting laminate 1. Therefore, the mechanical strength of the side portion of the oxide superconducting wire A is increased, the end portions 42b and 42b in the width direction of the superconducting portion 42 (particularly the end portions 5b and 5b in the width direction of the oxide superconducting layer 5) are protected, Damage can be prevented. Moreover, water resistance can be improved by improving the adhesiveness of the metal stabilization layer 28 with respect to the oxide superconducting laminated body 1. FIG.

  In the oxide superconducting wire C, since the covering portion 32 is directly bonded to the base material 3, the mechanical strength of the side portion of the oxide superconducting wire C is further increased as compared with the oxide superconducting wires A and B. Can do. Moreover, water resistance can further be improved.

FIG. 12 is a diagram showing a superconducting coil 100 which is an example of a superconducting coil.
The superconducting coil 100 is configured by laminating a plurality of coil bodies 101.
The coil body 101 is configured by winding an oxide superconducting wire 102. As the oxide superconducting wire 102, at least one of oxide superconducting wires A, B, and C shown in FIGS. 1, 7, and 9 can be used.
The coil body 101 is a pancake coil, and an oxide superconducting wire 102 is laminated and wound in the thickness direction. The pancake coil is a coil configured by winding a tape-shaped oxide superconducting wire so as to be wound repeatedly. The coil body 101 of the superconducting coil 100 shown in FIG. 12 has an annular shape. The plurality of coil bodies 101 may be electrically connected to each other.

  Since the superconducting coil 100 is configured by laminating a plurality of coil bodies 101, there is a possibility that a large compressive force in the coil thickness direction (wire width direction) may act on the coil body 101 by energization. Since the superconducting wires A, B, and C do not easily affect the oxide superconducting layer 5 in the width direction, it is possible to avoid deterioration of the characteristics of the superconducting coil 100 due to damage to the covering portion 2 or the like.

The embodiment of the present invention has been described above. However, the configuration in the embodiment is an example, and the addition, omission, replacement, and other modifications of the configuration can be made without departing from the spirit of the present invention.
For example, in the oxide superconducting wire A shown in FIG. 1, at least a part of the protective layer 6 and the bonding metal layer 7 may be integrated. The protective layer 6 and the bonding metal layer 7 may be collectively referred to as a protective layer.
In the oxide superconducting wire B shown in FIG. 7, at least a part of the protective layer 6, the first bonding metal layer 7, and the second bonding metal layer 27 may be integrated. Two or more of the protective layer 6, the first bonding metal layer 7, and the second bonding metal layer 27 may be collectively referred to as a protective layer.
In the oxide superconducting wire C, a covering tape having a structure in which a bonding metal layer is provided on both surfaces of the metal tape is employed. However, the covering tape may have a structure in which a bonding metal layer is provided on both surfaces of the metal tape. .

The coil body 101 of the superconducting coil 100 shown in FIG. 12 has an annular shape when viewed in parallel with the central axis of the coil body 101. However, the shape of the coil body 101 is not limited to the annular shape, and is an oval shape (race track shape). Alternatively, it may be oval. The number of coil bodies 101 constituting superconducting coil 100 may be an arbitrary number of 2 or more.
In the oxide superconducting wire A shown in FIG. 1, the end portion 5 b in the width direction of the oxide superconducting layer 5 is closer to the center than the end portion 11 b in the width direction of the main portion 11 over the entire length of the oxide superconducting layer 5. However, even when only a part in the length direction is closer to the center than the end portion 11b in the width direction of the main portion 11, an effect of preventing characteristic deterioration due to damage of the covering portion 2 or the like can be obtained.

The joining metal layer 7 of the oxide superconducting wire A shown in FIG. 1 covers the entire outer surface of the oxide superconducting laminate 1, but the region covered by the joining metal layer is the entire outer surface of the oxide superconducting laminate. It does not have to be. For example, the bonding metal layer can be configured to cover at least one side surface of the superconducting portion. In that case, the joining metal layer is interposed between at least one side surface of the superconducting portion and the metal stabilizing layer.
The joining metal layer may be configured to cover at least one side surface of the superconducting portion and at least one side surface region. In that case, the bonding metal layer is interposed between at least one side surface and at least one side surface region of the superconducting portion and the metal stabilizing layer.
In producing the oxide superconducting wire A shown in FIG. 1, as shown in FIGS. 3 to 6, the method of removing the side portion 13 of the superconducting portion 12 </ b> A by etching is illustrated, but the manufacturing method of the third embodiment Similarly to the above, laser processing may be employed.

  DESCRIPTION OF SYMBOLS 1 ... Oxide superconducting laminated body, 5 ... Oxide superconducting layer, 5b ... End of width direction of oxide superconducting layer, 7 ... Joining metal layer, first joining metal layer, 8, 28 ... Metal stabilization layer, 11 ... main part, 11a ... one side of main part, 11b ... end part in width direction of main part, 11d ... side face, 12, 12A ... superconducting part, 14 ... laser beam machine, 27 ... second bonding metal layer, 28A ... Metal tape, 100 ... Superconducting coil, A, B, C ... Oxide superconducting wire, C1 ... Center in the width direction, L1 ... The widthwise end of the main part and the widthwise end of the oxide superconducting layer Distance in the width direction, T1... Thickness of the covering portion on the side surface of the superconducting portion (total thickness of the bonding metal layer and the metal stabilizing layer on the side surface of the superconducting portion).

Claims (9)

An oxide superconducting laminate, a metal stabilizing layer covering the oxide superconducting laminate, and a joining metal layer joining the metal stabilizing layer to the oxide superconducting laminate,
The oxide superconducting laminate has a main part having a tape-like substrate and a superconducting part having an oxide superconducting layer,
The superconducting part is narrower than the main part and is laminated on one surface of the main part,
The joining metal layer is an oxide superconducting wire that is interposed at least between at least one side surface of the superconducting portion and the metal stabilizing layer.   The total thickness of the bonding metal layer and the metal stabilizing layer on the side surface of the superconducting portion is the distance in the width direction between the end portion in the width direction of the main portion and the end portion in the width direction of the oxide superconducting layer. The oxide superconducting wire according to claim 1, which is large.   3. The at least one end in the width direction of the oxide superconducting layer is located 300 μm or more closer to the center in the width direction than the end in the width direction of the main portion in plan view. Oxide superconducting wire.   The oxide superconducting wire according to any one of claims 1 to 3, wherein the metal stabilizing layer is a plating layer.   The oxide superconducting wire according to any one of claims 1 to 3, wherein the metal stabilizing layer is made of a metal tape.   A superconducting coil comprising the oxide superconducting wire according to any one of claims 1 to 5. A step of producing an oxide superconducting laminate comprising a main part having a tape-shaped substrate and a superconducting part having an oxide superconducting layer, wherein the superconducting part is laminated on one surface of the main part;
Removing the part of the superconducting portion in the width direction to form the superconducting portion so that the width is narrower than the main portion;
Forming a metal stabilizing layer that covers the oxide superconducting laminate, and a bonding metal layer that joins the metal stabilizing layer to the oxide superconducting laminate, and
In the step of forming the metal stabilizing layer and the bonding metal layer, manufacturing the oxide superconducting wire in which the bonding metal layer is interposed at least between at least one side surface of the superconducting portion and the metal stabilizing layer. Method.   The method for producing an oxide superconducting wire according to claim 7, wherein in the step of forming the superconducting portion so that the width is narrower than the main portion, a part of the superconducting portion in the width direction is removed by laser processing.   The method for manufacturing an oxide superconducting wire according to claim 7, wherein in the step of forming the superconducting portion so that the width is narrower than the main portion, a part of the superconducting portion in the width direction is removed by etching.

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